Monocrome Screw-Fit 41 mm Bottom Bracket for replacement and upgrade of press-fit BB86 and BB92 bottom brackets. Designed and engineered here at Shockcraft to solve fitment, creaking and bearing life issues.
Takes standard 6805 bearings with plastic caps. Optional Big Steel bearings with rubber gaskets for those who don't like plastic.
Bearings available in Chromium Steel, Stainless Steel or Ceramic Hybrid.
Fully rebuildable and upgradable.
6 months for Chromium Steel or Stainless Steel bearings without CNC Storm Drains
12 months for Stainless Steel bearings with CNC Storm Drains.
Unscrew the two cups from the centre sleeve and ensure grease is applied to the o-rings (right around) and the threads (one stripe across is enough).
Suitable greases include Slickoleum and Motorex Bike Grease 2000.
For MTB installation (89.5 or 92 mm wide shell) use one 4.5 mm spacer in one cup. Thread that side on the centre sleeve to trap the spacer in position.
For road installation (86 mm shell) discard the internal 4.5 mm spacer.
For GXP use with SRAM/Truvativ cranks install the 22 mm green Engagement rings into one cup. This is your non-drive side.
For 89.5 mm shell you must fit a 2.5 mm spacer (purchased separately here) on the drive side (unless a 2.5 mm BB mounted derailleur or chain-guide is fitted in that location).
Lightly grease the 41 mm diameter seating surfaces on each cup.
Slide the cup with the attached centre-sleeve into the BB and use a soft-faced hammer (plastic, rubber or wood) to tap the edges of the cup to seat it square into the frame enough to start the engagement. Ensure the centre sleeve visible from the other side is concentric.
Thread the other cup in from the other side with your fingers. Once it has engaged the threads and pulled up you can use a tool (IceToolz 11D3 or Park BBT-18) to tighten and pull both sides in.
40 Nm is the required torque. A 32 mm socket & torque wrench can be used with the IceToolz 11D3. There is no torque wrench fitting on the Park BBT-18. You can get a feel for 40 Nm by trapping the square drive end of a torque wrench in a vise and feeling the force required on a similar length lever.
If the BB doesn't seat easily, it is better to remove and regrease before trying again.